Lumbar spine fusion, or arthrodesis, is a surgical procedure that is performed to fuse two or more vertebrae together. During the procedure, a surgeon places a bone graft or other biological and/or scaffold material that is intended to promote new bone growth between two or more vertebrae. One form of fusion involves removing the majority of the intervertebral disk and replacing the disk with a structural cage that holds bone graft or other material. The spine segments being fused may be stabilized with spinal instrumentation such as a plate and screws. This type of fusion can be performed through a direct lateral or anterolateral retroperitoneal surgical approach. Spinal fusion surgery can be used to relieve nerve generated pain, and to treat ailments such as lumbar degenerative disk disease, spinal stenosis, lumbar spondylolisthesis, and scoliosis.